noeifevo 43 8v 2a lifepo4 battery charger for 12s 36v 38 4v lifepo4 battery with lcd display cooling fan automatic shutdownDue to some batteries with M25 charging connectors that have integrated charging protocols, our charger cannot support batteries with built in charging protocols. Please confirm with the battery supplier before purchasing whether the battery has an integrated charging protocol. For M25 (2+1+5) and M25 (2+4), the standard polarization is 1+ for positive and 2 for negative. If you require a different polarization, please inform us. Contact options: You